Subject lines that get opened
Include Invoice, your number, and a reference they recognize:
- Invoice #INV-0042 — Website redesign
- Invoice for March retainer — due 20 Apr 2026
- Payment request: Invoice #INV-0042 (Your Name Studio)
Body template (first send)
Hi [Name], please find invoice #[number] for [one-line summary] attached as a PDF. Total due: [amount] by [due date]. Pay via [method / reference]. Thanks — [Your name].
One optional sentence is enough for warmth (“Happy to walk through the line items if helpful”). Do not bury the due date.
Attachments and naming
Name the file so AP can search it: INV-0042-YourName-Client.pdf. Create the PDF with download invoice PDF tips or the free generator.
Match payment terms on the PDF and in the email so nothing conflicts.
Follow-ups without sounding harsh
If payment is late, keep the same invoice number and attach the same PDF. State the original due date and what is still owed — see late payment reminder.
Do not invent a new invoice number for a chase email; that confuses accounting systems.
Create the PDF first, then send
Build the bill in a free invoice generator — logo optional, no signup — download PDF, then paste one of the subject lines above. Freelancers can start from the freelance invoice generator.
Still deciding estimate vs invoice? Read invoice vs estimate before you email the wrong document type.
Disclaimer
Email templates are practical examples, not legal notices. For overdue accounts, follow your contract and local rules; start with a calm reminder before escalation.